Darren Chester has declared there’s “about a 95% chance” the Nationals will line up behind a net zero target because “Barnaby Joyce can count, and the majority of the room is in favour of credible action”.

The Victorian National, who is currently on a break from his party room because of escalating tensions with Joyce on a range of fronts, told ABC local radio on Tuesday he believed Scott Morrison would land the net zero commitment.

“Three months ago, Barnaby Joyce said there was zero chance the Nationals would support a net zero target,” Chester said. “I think that’s changed dramatically in the last two months”.

“Now he is talking far more constructively about that, because despite all his other faults, Barnaby Joyce can count, and the majority of the room is in favour of credible action on climate change”.

Joyce told the ABC on Tuesday night that no deal was done, and indicated the Nationals party room would make a “prudent assessment” based on “whatever is required to leave [people in the regions] in the same or better condition – preferably … striving for better”. “But don’t take them backwards,” he said.

Chester – who supports a net zero commitment – stepped back from the National party in September citing “months of frustration with the repeated failure of the leadership to even attempt to moderate some of the more disrespectful and offensive views expressed by a minority of colleagues”.

It is unclear whether the Victorian former frontbencher – who was demoted by Joyce when he returned to the leadership in the middle of the year – will rejoin his colleagues when the Nationals party room meets on Sunday ahead of the resumption of federal parliament.

The meeting will consider whether or not a majority of Nationals MPs support Morrison’s objective to commit to net zero ahead of the Cop26 summit in Glasgow.

Nationals frontbenchers Bridget McKenzie, David Littleproud and Keith Pitt were briefed for the first time on Monday afternoon on the roadmap that has been worked up by the energy and emissions reduction minister, Angus Taylor, with input from across the government.

The roadmap includes assessments about when particular technologies would kick in to enable a transition to net zero emissions by mid-century.

During the leadership group session on Monday afternoon, Taylor was asked by colleagues to supply more detail about the economic analysis underpinning the new proposed roadmap before the next cabinet-level meeting.

Nationals are particularly focused on the impact of the transition on regional employment, and Monday’s presentation was felt to be lacking in detail. The plan will go to cabinet on Wednesday.

While Chester is upbeat about Morrison’s chances of securing agreement ahead of Glasgow, not all Nationals are. Some insist the negotiation has a long way to go, and internal perceptions vary about the level of base support inside the Nationals for a climate policy pivot.

Joyce told ABC’s 7:30 that he won’t “support net zero without the support of my colleagues”, adding that the “worst thing” he could do is declare that he had “determined that this is the direction the Nationals are going”. “I’m not going to do it.”

Underlining the need for diligence, Joyce said that after the Kyoto climate agreement the Nationals’ constituents had been “done over”.

“People played a sneaky little game. And we ended up with the divestment of our private property,” he said, citing the fact state laws stripped farmers of the right to clear vegetation on their land.

Joyce said he did not believe Morrison and Taylor were playing sneaky games but it was a matter of “we’ve been once bitten, and twice, we’re going to be diligent”.

Littleproud, the agriculture minister, said on Tuesday some Nationals would continue to reject a net zero commitment even if there was majority support. He said “the party room want[ed] to understand the detail in the plan to make sure we have comfort in the details and the modelling”.

“Until we see it, this is all hypothetical,” he told Sky News on Tuesday.

Asked by reporters in Brisbane whether the Nationals would countenance an increase in the Coalition’s 2030 target as well as a new mid-century commitment, Littleproud said: “We’re going to go past the Paris commitment anyway in terms of the trajectory of our achievement”.

“But the net zero by 2050 is the game in which we have been asked to sign up to and when we sign up to it, we’ll mean it,” he said.

Courtesy of a recent commitment by the New South Wales government, and with other states contributing to the heavy lifting on emissions reduction, Morrison would now be in a position to unveil a 34% cut in national greenhouse gas emissions by 2030 based on existing pledges if he chose to, rather than sticking to the current national 2030 target of a 26 to 28% cut.

With the negotiations with the Nationals heading for crunch point, Taylor has used two speeches this week to try to reassure wavering MPs that a net zero commitment doesn’t mean the demise of traditional industries.

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Taylor flagged the use of carbon offsets to shield heavy emitters at a conference on Monday. On Tuesday he told the Committee for Economic Development of Australia a net zero commitment would not damage “our greatest economic strengths”.

Taylor said he did not want to see agriculture, heavy industries and resources “badly damaged” during the transition – “and they don’t need to be.”

“They do need to adapt, there’s no question about that,” the minister said. “But a sensible net zero goal with a sensible net zero pathway creates a pathway for our resources industry, our heavy industry and our agriculture”.

Taylor said the government’s approach to managing the transition was one of “carrots, not sticks”.

“We don’t want to impose costs on Australian businesses, particularly households and small businesses, but we do see an enormous role for technology to play working with customers,” he said.